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Posts Tagged: Reveton

Not long ago, miscreants who wanted to buy an exploit kit — automated software that helps booby-trap hacked sites to deploy malicious code — had to be fairly well-connected, or at least have access to semi-private underground forums. These days, some exploit kit makers are brazenly advertising and offering their services out in the open, marketing their wares as browser vulnerability “stress-test platforms.”

Styx Pack victims, by browser and OS version.

Aptly named after the river in Greek mythology that separates mere mortals from the underworld, the Styx exploit pack is a high-end software package that is made for the underground but marketed and serviced at the public styx-crypt[dot]com. The purveyors of this malware-as-a-service also have made a 24 hour virtual help desk available to paying customers.

Styx customers might expect such niceties for the $3,000 price tag that accompanies this kit. A source with access to one Styx kit exploit panel that was apparently licensed by a team of bad guys shared a glimpse into their operations and the workings of this relatively slick crimeware offering.

The Styx panel I examined is set up for use by a dozen separate user accounts, each of which appears to be leveraging the pack to load malware components that target different moneymaking schemes. The account named “admin,” for example, is spreading an executable file that tries to install the Reveton ransomware.

Other user accounts appear to be targeting victims in specific countries. For example, the user accounts “IT” and “IT2” are pushing variants of the ZeuS banking trojan, and according to this Styx panel’s statistics page, Italy was by far the largest source of traffic to the malicious domains used by these two accounts. Additional apparently country-focused accounts included “NL,” AUSS,” and “Adultamer” (“amer” is a derisive Russian slur used to describe Americans).

An exploit kit — also called an “exploit pack” (Styx is marketed as “Styx Pack”) is a software toolkit that gets injected into hacked or malicious sites, allowing the attacker to foist a kitchen sink full of browser exploits on visitors. Those visiting such sites with outdated browser plugins may have malware silently installed.

Unlike other kits, Styx doesn’t give a detailed breakdown of the exploits used in the panel. Rather, the panel I looked at referred to its bundled exploits by simple two-digit numbers. This particular Styx installation used just four browser exploits, all but one of which targets recent vulnerabilities in Java. The kit referred to each exploit merely by the numbers 11, 12, 13 and 32.

According to the considerable legwork done by Kafeine, a security blogger who digs deeply into exploit kit activity, Styx Kit exploit #11 is likely to be CVE-2013-1493, a critical flaw in a Java browser plugin that Java maker Oraclefixed with an emergency patch in March 2013. Exploit 12 is almost certainly CVE-2013-2423, another critical Java bug that Oracle patched in April 2013. In an instant message chat, Kafeine says exploit #13 is probably CVE-2013-0422, a critical Java vulnerability that was patched in January 2013. The final exploit used by the kit I examined, number 32, maps to CVE-2011-3402, the same Microsoft Windows font flaw exploited by the Duqu Trojan.

The Styx stats page reports that the hacked and malicious sites used by this kit have been able to infect roughly one out of every 10 users who visited the sites. This particular Styx installation was set up on June 24, 2013, and since that time it has infected approximately 13,300 Windows PCs — all via just those four vulnerabilities (but mostly the Java bugs).

The author of Blackhole, an exploit kit that booby-traps hacked Web sites to serve malware, has done so well for himself renting his creation to miscreants that the software has emerged as perhaps the most notorious and ubiquitous crimeware product in the Underweb. Recently, however, the author has begun buying up custom exploits to bundle into a far more closely-held and expensive exploit pack, one that appears to be fueling a wave of increasingly destructive online extortion schemes.

Cool Exploit Kit.

An exploit pack is a software toolkit that gets injected into hacked or malicious sites, allowing the attacker to foist a kitchen sink full of browser exploits on visitors. Those visiting such sites with outdated browser plugins may have malware silently installed. In early October 2012, security researchers began noticing that a new exploit pack called Cool Exploit Kit was showing up repeatedly in attacks from “ransomware,” malicious software that holds PCs hostage in a bid to extract money from users.

“Kafeine,” a French researcher and blogger who has been tracking the ties between ransomware gangs and exploit kits, detailed Cool’s novel use of a critical vulnerability in Windows (CVE-2011-3402) that was first discovered earlier in the year in the Duqu computer worm. Duqu is thought to be related to Stuxnet, a sophisticated cyber weapon that experts believe was designed to sabotage Iran’s nuclear program.

About a week after Kafeine highlighted the Duqu exploit’s use in Cool, the same exploit showed up in Blackhole. As Kafeine documented in another blog post, he witnessed the same thing happen in mid-November after he wrote about a never-before-seen exploit developed for a Java vulnerability (CVE-2012-5076) that Oracle patched in October. Kafeine said this pattern prompted him to guess that Blackhole and Cool were the work of the same author or malware team.

“It seems that as soon as it is publicly known [that Cool Exploit Kit] is using a new exploit, that exploit shows up in Blackhole,” Kafeine said in an interview with KrebsOnSecurity.

As detailed in an excellent analysis by security firm Sophos, Blackhole is typically rented to miscreants who pay for the use of the hosted exploit kit for some period of time. A three-month license to use Blackhole runs $700, while a year-long license costs $1,500. Blackhole customers also can take advantage of a hosting solution provided by the exploit kit’s proprietors, which runs $200 a week or $500 per month.

Blackhole is the brainchild of a crimeware gang run by a miscreant who uses the nickname “Paunch.” Reached via instant message, Paunch acknowledged being responsible for the Cool kit, and said his new exploit framework costs a whopping $10,000 a month.

At first I thought Paunch might be pulling my leg, but that price tag was confirmed in a discussion by members of a very exclusive underground forum. Not long after Kafeine first wrote about Cool Exploit Kit, an associate of Paunch posted a message to a semi-private cybercrime forum, announcing that his team had been given an initial budget of $100,000 to buy unique Web browser exploits, as well as information on unpatched software flaws. Here is a portion of that post, professionally translated from Russian:

The U.S Federal Bureau of Investigation is warning about an uptick in online extortion scams that impersonate the FBI and frighten people into paying fines to avoid prosecution for supposedly downloading child pornography and pirated content. This post offers an inside look at one malware gang responsible for orchestrating such scams.

Reveton ransomware scam page impersonating the FBI

In an alert published last week, the FBI said that The Internet Crime Complaint Center — a partnership between the FBI and the National White Collar Crime Center — was “getting inundated with complaints” from consumers targeted or victimized by the scam, which uses drive-by downloads to hijack host machines. The downloaded malware displays a threatening message (see image to the right) and blocks the user from doing anything else unless he pays the fine or finds a way to remove the program.

The FBI alert said the attacks have surged with the help of a “new drive-by virus” called Reveton; in fact, Reveton and its ilk are hardly new. These types of attacks have been around for years, but traditionally have targeted European users. The scam pages used in the attacks mimic official notices from various national police or investigatory agencies, corresponding to the country in which the victim resides. For a breakdown of these Reveton-related ransomware scam pages by country, see this comprehensive gallery set up at botnets.fr.

Reveton.A is blamed in these most recent attacks, and the FBI said it appears Reveton is being distributed in conjunction with Citadel, an offshoot of the ZeuS Trojan that I have writtenabout on several occasions. It is certainly possible that crooks are using Citadel to deploy Reveton, but as I’ll illustrate below, it seems more likely that the attackers in these cases are using exploit kits like BlackHole to plant both threats on victim PCs.

INSIDE A REVETON MALWARE GANG

Operations of one Reveton crime group. Source: ‘Kafeine,’ from botnets.fr.

At least that’s the behavior that’s been observed by a ragtag group of researchers that has been tracking Reveton activity for many months. Some of the researchers are associated with botnets.fr, but they’ve asked to remain nameless because of the sensitivity of their work. One of them, who goes by the screen name “Kafeine,” said much of the Reveton activity traces back to a group that is controlling the operation using reverse proxies at dozens of servers scattered across data centers globally (see this PDF for a more detailed look at the image above).

Kafeine said the groups involved in spreading Reveton are constantly fine-tuning all aspects of their operations, from the scam pages to solidifying their back-end hosting infrastructure. The latest versions of Reveton, for example, serve the scam pages from an encrypted (https://) connection, and only cough up the pages when an infected machine visits and sends a special request. Continue reading →